Episode list

During a stormy night, Mark Hollander plays a video game, Ace Lightning and the Carnival of Doom, discovering a seventh level that should not exist. A lightning bolt strikes the house, causing the game's characters to come to life in Mark's backyard. Ace Lightning recruits Mark as his sidekick to collect the pieces of the Amulet of Zoar, and capture his arch nemesis Lord Fear, who takes up residence at the rundown Kent Bros. Carnival. Mark starts his first day at Conestoga Hills Middle School, and later receives a piece of the Amulet from Ace. Ace finds the carnival but is captured by Lord Fear's gang.

Mark informs his friend Pete about the game coming to life. Ace is imprisoned and tortured by Lord Fear and his minions. Mark, accompanied by his new friend Chuck Mugel, travels to the carnival and tries to rescue Ace, but flees. That night, the carnival opens to the public, allowing Mark to sneak back in and free Ace. He then discovers Dirty Rat, disguised as a stuffed rabbit, plans to bomb Samantha Thompson and Brett Ramirez. Mark throws the rat skyward, Ace grabbing the bomb and disposes of it.

Lord Fear and Pigface kidnap Mark's science teacher, Mr. Cheeseborough, and replace him with Lady Illusion in disguise, as part of a trap to destroy Mark. In class, Lady Illusion puts Mark and Chuck in detention. Realising something is amiss, Mark searches the carnival for the real Mr. Cheeseborough but is cornered by Pigface and Dirty Rat, Ace rescuing him. Samantha instead finds Mr. Cheeseborough, discovering he is being used as a sideshow.

Mark tries to skip school but his parents encourage him to go to detention. On the way to school, the school bus is pursued by Lord Fear and Duff Kent in their ice cream truck, but Ace causes them to crash. Mark helps Ace sneak into the school, while Lord Fear deploys Pigface to back up Lady Illusion. Dirty Rat hypnotises Mr. Cheeseborough to erase his memory of his abduction and then frees him. During detention, Lady Illusion shows a gas bomb at the boys, Chuck becoming delirious. Mark and Chuck flee to the cafeteria, where Ace engages Lady Illusion and Pigface in battle til they flee. Mark worries about Chuck knowing his secret, but Ace reassures him that he won't remember once the gas wears off.

Ace begins to lose energy without a reliable power source to recharge. Mark's class visit Conestoga Hills' observatory, where Chuck tells the urban legend of the Radioactive Guy, a scientist who went mad after being exposed to the radioactive waves of a comet. Mark's cousin Ashley meets Ace, mistaking him for the Radioactive Guy. Ace continues to lose power but comes to Ashley's rescue when she wanders in the carnival alone. Mark takes Ace to the observatory where he is able to recharge, chasing off the villains. Ace decides to live in the observatory, naming it the Thunder Tower. Ashley promises to keep Ace a secret.

Lady Illusion strikes out on her own to find a way back home, stealing Lord Fear's piece of the Amulet. Mark's romance with Samantha is jeopardised when he learns Ace has captured Lady Illusion. However, to Mark's surprise, the two wayward superhumans fall in love. Dirty Rat informs Lord Fear who storms the Thunder Tower to win back his lady. Lady Illusion claims she was trying to steal Ace's piece of the Amulet, which Lord Fear falls for. When Lady Illusion connects the Amulet pieces together, it summons the Lightning Lance, which chases off the villains. At the end of the episode, Mark is able to rebuild his relationship with Samantha.

Lord Fear gains another piece of the Amulet, using it summon the maniacal jester Googler and his puppets Zip and Snip. When Googler confronts Ace, his puppets zap Ace of his superpowers. Ace disguises himself as a police officer and turns to Mark for help, believing he is useless without his powers. Mark rescues Chuck and Samantha from a decrepit treehouse. Ace is lured away by Dirty Rat, allowing Mark to be knocked out by Googler and taken to the carnival, where he is placed into a dunking tank to be devoured by Zip and Snip. Ace confronts the villains, understanding the importance of Mark as a friend, regaining his powers and frees his sidekick.

On Halloween, Mark throws a party at his house but has to rescue Chuck when Pigface and Dirt Rat mistake him for Ace, since he is wearing an Ace Lightning costume. Meanwhile, Duff turns to Ace for help to rid himself of Lord Fear. When they go to confront Fear, Duff chickens out and tries to set up Ace into a trap, but the superhero escapes, also rescuing Mark and Chuck from their pursuers.

Dirty Rat obtains Ace and Lord Fear's pieces of the Amulet in an attempt to summon his own minion, leading to the arrival of the cyborg Random Virus, Ace's old friend, who suffers from two conflicting programs. Mark is terrified of Random, but plucks up the courage to confront him when Dirty Rat commandeers Chuck's experimental robot to use as a secondary weapon. Ace comes to aid him, Lord Fear also arriving when Duff informs him of the rat's schemes. Mark rescues Chuck's robot and returns it to him so he can win a science competition, while Ace promises to keep an eye on Random, who lives in the town's junkyard.

Mark discovers Samantha has gained a part-time job at the carnival and attempts to dissuade her from taking it. Lady Illusion informs Ace of a plan by Lord Fear to use Samantha as bait, but upon returning to the carnival, it is revealed she is in on a secondary trap. Mark and Ace decide to spy on Samantha during her first day, disguised as a girl and a motorcyclist. Wayne Fisgus falls for Mark's girly disguise and flirts with "her". After the carnival closes, Samantha finds herself locked in and under attack by Zip and Snip. Mark rescues her and Chuck, while Ace battles Googler. Lady Illusion throws a bomb at Ace, deliberately missing and hits Googler instead, though Lord Fear dismisses it as a fluke.

Lord Fear kidnaps Random, prompting Mark to help Ace search for him. Mark turns to Chuck for help finding a way to prevent Random from turning evil in the video game, but Samantha, fed up with Mark's constant excuses, dumps him and goes out with Brett. Mark, determined to win Samantha back, follows her onto the Tunnel of Love with Chuck in tow. Inside, he spots Random and goes to rescue him. Lord Fear appears, convincing Random to join his side. Ace crashes in through the roof armed with the Shield of Justice and tosses it to Mark, using its abilities to blast Random with a deflected lightning bolt, restoring his sense of reason. Samantha confronts Mark outside, realising how far he will go to win her back and they get back together.

Mark's social life begins to collapse around him. His grades are failing, his parents ground him, and his relationships sour while Ace struggles to retrieve a new Amulet piece from the carnival. Lord Fear stalks and later kidnaps Mark to seize his piece of the Amulet. Ace rescues Mark and fights the villains while Mark obtains the new Amulet piece, summoning Sparx. However, her condescending comments to Mark causes him to quit being a Lightning Knight.

During a battle against the villains, Ace is zombified by Googler's puppets, rendering him a brainless slave at Lord Fear's command. Sparx flees from Ace, and turns to Mark for help, who is rebuilding his life after quitting the role as Ace's sidekick. However, he has a change of heart when the brainwashed Ace attacks Sparx in his backyard and then targets him. With Chuck's help, Ace is freed of his brainwashing and saves Sparx from Lord Fear. Mark becomes a hero again, earning Sparx's apology and respect.

Mark dreads going on a field trip to the carnival, and decides to be honest with Samantha about his feelings and his secret life. At the Thunder Tower, Anvil destroys the Lightning Knights' transformer. Ace tries to repair it, while the rambunctious Sparx decides to take the fight to Lord Fear, but is instead used as bait to lure Ace. Mr. Cheeseborough and the other students are trapped, while the game characters duel. Mark and Samantha free their friends, while Ace and Sparx fight Lord Fear. At the end of the episode, Lord Fear plots to invade Mark's home.

Mark, Chuck, and Ashley have a horror night, but their night does not go according to plan. Lord Fear, Staff Head, Dirty Rat, and Pigface invade the house, but mostly cause mayhem for themselves. Lord Fear gets stuck in the chimney, Dirty Rat is chased out of the house by a frightened Chuck, Pigface raids a pizza delivery van, and Staff Head is left behind when the villains ultimately retreat. In a subplot, Lady Illusion attempts to assassinate Sparx, leading to a cat fight with Ace caught in the middle.

Chuck records Sparx flying overhead on film and mistakes her for an alien, causing a frenzy around town. Googler is accidentally stranded in town and becomes lost when Duff's ice cream truck is taken to the pound, but Lord Fear and Duff later steal it back. Sparx grows overconfident in her skills and wishes to fight Googler, against Ace's advice. Mr. Cheeseborough, having regained his memories of his kidnapping, assumes the villains are aliens and plans to use a homemade radar to locate them. Mark volunteers, but the radar attracts Googler to the school. Sparx confronts Googler, but Zip and Snip grab her sword and blast her back into the game.

Mark's friend Pete visits him, but his easygoing attitude and knack for just about everything makes Mark jealous of him. Pete is eventually targeted by Lord Fear and taken prisoner until Mark hands over his piece of the Amulet. Meanwhile, Random Virus tries to join the villains, but a distrusting Lord Fear chains him up. Random eventually breaks free and goes on a rampage, forcing Ace and Lord Fear to join forces to knock him out, who agree on a truce until their next battle. Pete decides to not meet Ace, believing he is unready, revealing he found life boring in England but decides it is worth living.

On April Fool's Day, Lady Illusion disguises herself as Mark and sabotages his social life in school, while the real Mark is at home with a cold. Lady Illusion, still pretending to be Mark, confronts Ace, but the real Mark enters when he realises something is wrong. Ace uses a practical joke to figure out which is the real one. Mark tries to patch things up with Samantha, but she breaks up with him, gaining the interest of her best friend Heather Hoffs, who has a crush on Mark.

Mark tries to recruit Random Virus for help, but his evil side prevents him from being a hero. Mark attempts to give Ace some upgrades with help from Chuck, but the latter's computer crashes, causing Ace to be petrified. Lady Illusion and Dirty Rat witness this, Lord Fear orchestrating Ace's capture. The villains celebrate their victory, but Mark storms the carnival with Random in tow. During the mayhem, Lady Illusion kisses Ace, reviving him. Staff Head witnesses this, discovering Lady Illusion's betrayal, and blackmails her into obedience.

In this clip show episode, Duff speaks to a psychiatrist about his ongoing involvement in the battle between Ace and Lord Fear. Believing the tale to be a moral issue, and caused by stress at work, the psychiatrist advises Duff to take it easy. Duff exits into the waiting room, recognising Mr. Cheeseborough as the next patient. When Duff leaves, the receptionist transforms into Lady Illusion, sent to spy on Duff.

During a fight between Ace and Lord Fear, Chuck is struck by a deflected lightning bolt, temporarily gaining superhuman strength, particularly in his foot, which he nicknames "Thunder Foot". He is made the key player of the school soccer team for an upcoming match against long-term rivals. Lord Fear mistakes Chuck for another of Ace's sidekicks and plots to destroy him at the school, while Ace is distracted at the carnival. Chuck's powers wear off during the soccer match, but the team still manage to win the game. At the end of the episode, Mark and Heather become a couple.

At the carnival, Ace finds a new piece of the Amulet. However, both he and the villains learn Mark has gone camping with his father Simon, Chuck, and Brett. At the campsite, Chuck eats all the food, so the group are invited to camp with Wayne and his boastful father Buck. That night, the villains attack the group but Mark uses Chuck's handheld copy of the game to frighten them away. Ace arrives shortly thereafter and uses the Amulet to summon Sparx back from the game world. Wayne and his dad flee during the night, and Simon is praised for defending the boys from the "wildlife", actually the villains.

Mark has a tough decision to make between going on a date with Heather, or helping Chuck run an Ace Lightning fan club meeting at the school. Lord Fear learns of the fan club and becomes jealous, planning to crash the meeting. Mark initially chooses to go with Heather, but upon learning Lord Fear's plan, changes his mind and sneaks Ace into the school. Chuck meets Wayne's cousin Jessica, also an Ace Lightning fan. Lord Fear crashes the meeting, but Ace leaps out and chases him out of the school, much to the cheers of the fans, who assume Chuck set it up.

When Samantha obtains the final piece of the Amulet, both factions hope to gain it during the school play of The Phantom of the Opera. Mark is attracted to Samantha again, and attempts to tell her but does not have the chance. During the performance, Chuck, who is playing the Phantom, throws up. While Mr. Cheeseborough despairs, Mark hijacks the narrative of the play when Lord Fear invades the stage, and is mistaken for Chuck (whose costume was based on Lord Fear's appearance). The play becomes a surprise success, and Dirty Rat obtains the Amulet piece. Sparx sneaks into the carnival but is taken captive by Lady Illusion.

Tired of Lord Fear's abuse, Dirty Rat is encouraged by Sparx to insight a rebellion against his master, rallying Anvil, Pigface, Googler, and Duff to his cause. Staff Head sends Lady Illusion to obtain the Lightning Knights' Amulet pieces or her secret will be exposed to Lord Fear. At school, Mr. Cheeseborough has been promoted to temporary principal, but he has introduced a Nineteen Eighty Four-like regime to the school. Chuck insights his own rebellion against Mr. Cheeseborough, but both he and Mark are summoned to his office. Lady Illusion, disguised as Sparx, convinces Mark to hand over his piece of the Amulet to her. Mr. Cheeseborough agrees to drop his rules if Mark protects him from the "aliens". Lady Illusion gives Lord Fear the collected Amulet pieces, and Dirty Rat surrenders his own, allowing Lord Fear to restore the Amulet. Mark realises he was duped and learns the Lightning Knights will lose power unless they find the Amulet.

The final battle is at hand. Ace and Sparx try to recruit Random to fight but he refuses to until Ace reminds him of how he used to be a hero. Mark learns from Chuck that he could delete his game file, which would erase the characters too. He speaks with Ace about the truth of the game, but Ace dismisses it and prepares for the battle. At the prom, Chuck worries Jessica won't come, and Heather dumps Mark in favour of Brett. Duff takes Mark to the carnival to find the Amulet, the Lightning Knights arriving shortly after. Lady Illusion reveals her treachery to Lord Fear, and Duff stands up to him. Mark sneaks into the haunted house during the battle. When he fails to beat the game, he considers deleting the file, but realises the Amulet is hidden in Lord Fear's pipe organ. Playing the right notes reveals the Amulet, which he shatters, sending all of the villains sans Lady Illusion back to the game. At the prom, Chuck is thrilled when Jessica arrives, and Mark gets back together with Samantha.